The Wilkinson and Schaller roller bridges are a 14' bridge radius, not 12".

The post spacing on the bridges is 74mm = 2.91339 inches.

If you have a 9.5 or 7.5 fretboard radius on your neck, then shimming these bridges is a good idea to compensate the difference.

I like the Ibanez de-7, the Mem Boy, and the Ekko 616 Mk II

Are you asking what the resistive value of the Rate pot on the memory Boy is? You can't open it and measure it with a voltmeter????